The exposure prompted a business boom for the divorce lawyers and private investigators in the capital city, which is Ashley Madison's No. 1 Canadian hookup hub and potentially the site's highest per capita globally.

"Everybody says Ottawa is a sleepy town and here we are with 200,000 people running around on each other," municipal employee Jon Weaks, 27, told Reuters.

Some 189,810 Ashley Madison users were registered in Ottawa, a city with a population of about 883,000. Those numbers make the capital the website's No. 1 Canadian hub — and potentially the highest per capita globally.

Ashley Madison assured customers it had secured the leak Tuesday, and offered to waive its $19 delete fee for subscribers wishing to remove their accounts.

The hacking collective, which calls itself "The Impact Team," busted into the site earlier this week and immediately posted some of the private information online. They threatened to release all of the records if Ashley Madison's owner, Toronto-based Avid Life Media, didn't meet the hackers' demands.

Some 189,810 Ashley Madison users were registered in Ottawa, a city with a population of about 883,000. (Mike Carroccetto/Getty Images)

"Full Delete netted ALM $1.7m in revenue in 2014. It's also a complete lie," the hacking group wrote. "Users almost always pay with credit card; their purchase details are not removed as promised, and include real name and address, which is of course the most important information the users want removed."

Ashley Madison said it removed all personal information that the intruders posted in their first release. It's not clear if the waived removal fee will deter the hackers from releasing more of the stolen data.

"My God, my phones will be busy," private investigator John Sullivan told the Ottawa Sun. "There's a lot of very nervous people walking the street."

He called the leak a "goldmine" for the city's divorce lawyers — but a disaster for healthy marriages.

"I saw the story last night and my partner came in this morning and said, 'Forget about same-sex marriages doubling the practice. This is going to be a balloon,' " New York City-based attorney Nancy Chemtob told CNN.

Ashley Madison, whose slogan is "Life is short. Have an affair," claims it has more than 37 million anonymous worldwide members. The hackers claim to have stolen sensitive information from every user.

ALM's chief executive, Noel Biderman, suggested the attack could be an inside job from someone who had access to the network.

"We're on the doorstep of (confirming) who we believe is the culprit," he told cybersecurity expert Bryan Krebs Sunday. "I've got their profile right in front of me, all their work credentials. It was definitely a person here that was not an employee but certainly had touched our technical services.